The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
In general, for a vehicle to be manufactured, about twenty thousand to thirty thousand components go through assembly processes.
In some instances, a vehicle body is produced at a first step of a process of manufacturing a vehicle. Product panels are produced by various types of press apparatuses, and the product panels are conveyed to a vehicle body factory, and a vehicle body in a white body (B.I.W.) state is made by assembling respective parts of the product panel.
In order to form the panel as described above, a forming process of pressing and forming the panel into a predetermined shape using various types of press apparatuses is carried out, and thereafter, processing work such as cutting, hole processing, bending, and warping is carried out during a press process such as trimming, piercing, flanging, and hemming.
Generally, the hemming process is carried out by pre-hemming work through an elliptical trajectory motion of a pre-hemming punch, and thereafter, completing the hemming process through a vertical motion of the hemming punch.
FIG. 1 illustrates a pre-hemming apparatus 10 in the related art. A pre-hemming punch 40 is positioned on a panel primarily by a latch cylinder 20 of two high capacity cylinders, and secondarily, the pre-hemming punch 40 transmits horizontally force by a hemming cylinder 30, and finally, hemming work is carried out for the panel.
However, two cylinders 20 and 30 are installed in the pre-hemming apparatus such that manufacturing costs become high, and the two cylinders 20 and 30 are simultaneously operated when the hemming work is carried out for the panel, such that time required to process the panel is increased.